Apparatus for the continuous ejection of material



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May 25, 1965 K. G. LUNDH 3,185,098 APPARATUS FOR THE CONTINUOUS EJECTION OF MATERIAL med March 1, 1962 BY 0M L@ ATTORNEY United States Patent C) adsense APPARATUS lit-% THE CGNTENUUS EEECUQN GF MATEREAL Karl Gustav Len-dh, Vadnz, Liechtenstein, assigner to Anstalt Undo, Vaduz, Liechtenstein Filed Mar. il, 1962, Ser. No. 176,757 3 Claims. (Cl. .lr03-@9) This invention relates to an apparatus for the continuons ejection of materials and refers more particularly to an apparatus for continuously press casting various `articles, `such as bars, hose and the like.

When synthetic gut mass or other material is pressed into tubes or the like, any change 'in pressure will result in Ia change in the diameter of the tube. Furthermore, a change in the outow speed results in a change in ten-sion in the material between the nozzle and the following ejection path, with the result that the article which is being formed by pressure is torn oil, -or that loops are formed therein.

An object of the present invention is to improve the construction and operation of prior `art devices.

Other objects of the present invention will become apparent in the course of the following specicat-ion, The present invention is concerned with .a device consisting of two piston-containing cylinders connected by conduits to a valve which is so constructed that it maintains a connection between the conduit transmitting the highest pressure to an outlet vfor the material, the piston-containing cylinders being `so arranged that they supply the material alternately to the outlet and are illed by the material during the inoperative piston stroke from a further pistoncontaining cylinder which is connected by a double cheek Valve with the outlet conduits of the irst two piston-ccntaining cylinders; each piston-containing cylinder is connected by a common connecting rod with a separate hydraulically operated piston-cylinder device; the piston rods of the first-mentioned piston-containing cylinders are provided -With recesses or projections which cooperate with contacts used to operate pumps actuating the hydraulically operated devices. As lhas been stressed already, it is of particular importance that during the entire period of operation the lspeed of ejection as well as the uniformity of the material remain unchanged and that this should include the time period when the work of ejecting the material is shifted from one piston-containing cylinder to the other piston-containing cylinder. The possibility of maintaining this operational requirement depends to a large extent upon arranging the `supply of the material to the first-mentioned piston-containing cylinders under uniform continuous pressure.

In accordance with the present invention the recesses or projections are karranged upon their respective piston rods in such manner that at the end of each stroke of the piston in the direction of ejection, the iirst projection of the eiectively operating piston rod actuates a contact which starts the operation of Ia pump belonging to the ineffective piston-containing cylinder, whereby after further movement of said piston rod, another recess or projection actuates the shut-oil contact of its pump and vice versa; the hydraulic piston-cylinder device or" the additional pistoncontaining cylinder is continuously connected by a valve with the conduit which is in the proces-s of transmitting pressure.

This device of the present invention maintains uniform operational pressure in the additional piston-containing cylinder which supplies the material, securing uniform supply of material to the rst-mentioned piston-containingV cylinders.

Furthermore, the device of the present invention has the advantage that no separate hydraulic drive for the hydraulic piston-cylinder device of the additional piston- Patented May 25, 1965 containing cylinder is required and that the hydraulic piston-cylinder device receives at all times material-supplying pressure which Iis adjusted to the first-mentioned piston-containing cylinders.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing shown by way of example, a preferred embodiment of the inventive idea.

The sole figure of the drawing is a diagram illustrating the apparatus of the present invention, some parts being `shown :in section.

The apparatus shown in the drawing includes two cylinders i and 2 for the ejection of the material under pressure. The cylinders l and 2 are connected by pipes with two inlets of a valve 3. The outlet 4 of the valve 3 is connected with a form press nozzle which -is not shown in the drawing. The valve 3 is yso constructed that it aiwaysconnects the outlet i with the conduit transmitting the highest pressure.

The material is supplied through la pipe 5 and a stop valve 6 to a supply `cylinder 7 the outlet pipe of which is connected with a double `check valve 8. The two outlets of the valve 8 are connected to the outlets of the cylinders l and 2, respectively.

The cylinder l contains a piston connected with a piston rod 9. The :cylinder 2 contains a piston connected with a piston rod lll. The cylinder 7 also contains a piston connected with a piston rod Ill. The drive of these devices `is effected by two hydraulic pumps 12 and 13 which are driven by motors ld and 15, respectively. The pumps l2 and 13 are supplied with the hydraulic liquid 17 from la `container 16. The pump l2 is connected with a cylinder E@ by a pipe l; similarly the pump 13 is connected with a cylinder 2l by 'a pipe 19. A branch pipe 22 is connected to the pipe i8, -while a branch pipe 23 is connected to the pipe 19. The two pipes 22 and 23 are connected to a valve device 26.1 which is connected to a cylinder 25. The cylinder 2@ contains a movable piston which is connected with the piston rod 9. The cylinder 2l contains a movable piston which is connected to the piston rod lt?. Similarly, the cylinder 25 contains a piston connected to the piston rod il. The pipes 18 and 19 carry check valves 26 and 27, respectively, which `are coupled with each other and which are used to regulate the operational speed of the apparatus. The pipe 1S is connected with a relief valve 28, while the pipe i9 is connected with a relief valve 29.

The front endrposition of the piston in the cylinder 1 is designated by the numeral 39 in the drawing, the rear end position of the piston in the cylinder 2t? i-s designated by the numeral 3l, the front end posit-ion of the piston in the cylinder 2 is designated by the numeral 32 and the rear end position of the piston in the cylinder 21 by the numeral 33. Y

The piston rod 9 carries projections 34, 36 and 38, while the piston rod lil carries projections 35, 37 and 39; these projections constitute contact-actuators cooperating with contact-carrying devices 40, 43, 44 and 41, 42, d5, respectively.

To prevent any possible damage to the apparatus, the cylinders 20, Z1 and 25 are provided with so-called safety conduits 46, 47 and 48, respectively, which transmit the ow of the hydraulic liquid to the container 16 in the event one of the pistons had been moved beyond its front end position 49, Si? and 51 respectively; in that case the piston in question would move beyond the opening of one of the above-mentioned conduits and then its movement would cease. Y

The operation of the apparatus is as follows:

Let it be assumed that the cylinder 7 has been lled with the material through the pipe 5, that the valve 6 is closed and that the hydraulic pump 12 is driven by its Si motor 14. Let it be further assumed that the cylinders 1 and 2 and their corresponding material conducting pipes contain material for the press casting.

The pump 12 pumps hydraulic liquid 17 from the container 16 through the pipe 18 to the cylinder 2t) and also pumps the liquid through the branch pipe 22 and the valve device 24 to the cylinder 25. Y

The valve device 24 is so constructed Vthat it connects to the cylinder 25 only that one of the two branch conduits 22 and 23 which has the greater pressure.

The pressure in the cylinder 2@ causes the movement of the piston rod 9 along with the pistons connected therewith, until the piston in the cylinder 1 is moved to its front end position 30. The pressure in the cylinder 25 moves the. piston rod 11 with the pistons connected thereto, whereby the piston in the cylinder 7 is moved in the direction of ejection of the press casting material. Pressure which is produced in the cylinder 1 and which may be about 400 at, is considerably greater than the pressure which is produced in the cylinder 7 and which may beV about 200 at.; the result is that thevalve 8 interrupts the connection between the cylinders 1 and 7 and maintains open the connection between the cylinders 2 and 7; this is the position of the valve 8 shown in the drawing. Furthermore, due to pressure prevailing in cylinder ll, the valve 3 has closed the connection to the cylinder 2. Thus the press material is ejected by the cylinder 1 through the valve 3 and the outlet 4.

During this phase of operations the cylinder 7 supplies Y the material under pressure through the valve S into the cylinder 2, the piston in the cylinder 2 being moved along with the piston rod 1t) and the piston in the cylinder 21 in the direction of the arrow shown within the cylinder 2 until the last-mentioned piston assumes its rear end position 33; no forces oppose this filling operation since the which the piston rod 9 with the pistons connected therewith is shifted in the direction opposite to that of the arrow shown within the cylinder 20, the piston in the cylinder 21'@ moving toward its rear end position 31. In the course of this movement of the piston rod 9, its projection 34 engages and actuates the contact device i9 which illuminates the second-mentioned signal lamp, thereby indicating the completed iilling of the cylinder in question.

As soon as the piston rod 10 is shifted to such an extent that its projection 37 will actuate the contact device 42, the electrical circuit of the motor 14 will be closed again and the pump 12 will begin to operate so as to build up pressure in the cylinder Ztl. At the time when complete operating pressure has been built up in the cylinder 20, the piston rod 1t? has been moved to such an extent that its projection 39 will actuate the contact device 45, thereby interrupting the supply of electrical current to the motor 15, switching oit the iirst mentioned'signal lamp and causing pressure to drop in the cylinders 2 and 21 and in the conduit 19. Then the valves 3, 3 and 24 are shifted t0 their initially described illustrated positions and a new operational cycle begins for the cylinders 1 and 20, while the cylinder 2 is being lled.

. rPhe operational cycle may be summarized as follows:

When one ofthe switching members i4 or 45 is actuated by its associated tripping member 38 or 39, the associated coils 4d' or Li5 of the magnetic switches 52 or 53, are energized to break the supply circuit of the motor 14 or 15, and to stop the motor. When one of the switching members i2 or 43 is actuated by its associated tripping member 37 or 36, the associated coil 42 or 43 of the magnetic switches 52 or 53 is energized to close the supply circuit of the motor 14 or 15, and to start the motor.

The following table represents the complete working cycle of the machine.

Working cycle Member Member Cylinder tripping Cylinder tripping Valve 24 Valve 8 Valve 3 Paco No. 1 stroke: Motor 14 contact 2 stroke: Motor 15 contact connects connects connects -i-extrude -l-extrude conduit conduit conduit -flll -illl 25 to- 7 to- 4 t0 pump 13 with its motor 15 are switched Gif. When theY cylinder 2 is full, the projection 2S of the piston rod 19 will engage the contact device 41, thereby lighting a signal lamp (not shown).

At the time when the piston in the cylinder 1 nears its front end position 3l), the projection 36 of the piston rod 9 will 'actuate the contact device 43 which closes a circuit supplying electrical current to the motor 15. The motor 15 connected to the pump 13 gradually begins to build up operating pressure in the cylinder 2l. When full operating pressure has been built up in cylinders 2 and 21, the piston rod 9 has been moved to such an extent that its projection 38' will engage and actuate the contact device 44 which switches off the electrical circuit of the motor 14 and at the same time switches oi another signal lamp (not shown); then the pump 12 stops and pressure ceases in the conduit 1S and the cylinder 2h. kThe valve device 24 is then automatically reversed, so that the branch pipe 23 is now connected to the cylinder 25 and pressure AYdevelops in the cylinder 275 as well as in the cylinder 7. The

valves 3 and 8 are reversed at the time when the cylinder 2 takes over the work of ejecting the material; thus the cylinder 2 is now connected with the outlet 4- through the valve 3, while the valve 8 has interrupted the connection between the cylinders 7 and 2 and has established the connection between the Ycylinders '7 and 1. Then begins the filling of the cylinder l with the material in the course of The above-described operational cycles can be continued without interruption until the contents of the supply cylinder 7 are exhausted. It pressure in the supply pipe 5 is somewhat greater than that in the cylinder 7, the cylinder 7 can be reiilled with material without interrupting the operation of the apparatus.

It is clearly apparent from the above description that the illustrated apparatus of the present invention attains all the above-indicated advantages.

It is further apparent that the example described above has been given solely by way of illustration and not by way of limitation and that it is subject to many variations and modifications within the scope of the present invcntion.

What is claimed is:

l. Apparatus for the continuous ejection of pressed material, comprising, in combination, two alternately operating presses, each of said presses comprising a cylinder, a piston movable in said cylinder, and piston-actuating means connected with said piston, the two pistons being movable in opposite directions from front end positions to rear end positions and vice versa; means forming a single outlet for the ejected material, means connected with the last-mentioned means and said cylinders for feeding the material to be pressed into a cylinder and causing the material to move the piston located in that cylinder into its rear end position before the piston in the other cylinder has reached its front end position, and a separate hydraulic device for moving the two pistons alternately from their rear end positions to their front end positions to alternately eject the material which has been fed to said pistons with substantially the same ejection speed through said outlet, said device comprising means actuated by the piston-actuating means of one piston while said one piston is being moved by the material toward its rear end position for moving the other piston from its rear end position to its front end position, and separate means actuated by the piston-actuating means of said other piston while said other piston is being moved by the material toward its rear end position for moving said one piston from its rear end position to its front end position, the two ylast-mentioned means moving a piston from its rear end position toward its front end position before the other piston has reached its front end position.

2. Apparatus for the continuous ejection of pressed material, comprising, in combination, tWo cylinders, pistons movable in said cylinders in opposite directions from front end positions to rear end positions and vice versa, outlet pipes connected with said cylinders, an outlet Valve connected with said outlet pipes and having an outlet and means connecting said outlet with that outlet pipe which is subjected to greatest pressure; a filling cylinder having an outlet opening, means connected with said lling cylinder for supplying the material thereto, a piston in said filling cylinder, and means actuating the last-mentioned piston to supply the material to said outlet opening, a valve connected with said outlet opening and said outlet pipes and having means connecting said outlet opening with that outlet pipe which is subjected to lesser pressure; separate piston rods connected with said pistons, separate pressure-producing means connected with said piston rods, two projections carried by one of said piston rods, two other projections carried by the other one of said piston rods, a separate contact-carrying device adapted to be engaged and actuated by each of said projections, and means connecting said contact-carrying devices with said pressure-producing means for moving a piston located in its rear end position toward its front end position when the other piston is adjacent its front end position and thereupon relieving pressure from the inst-mentioned piston.

3. Apparatus for the continuous ejection of pressed material, comprising, in combination, two cylinders, pistons movable in said cylinders in opposite directions from ront end positions to rear end positions and vice Versa, outlet pipes connected with said cylinders, an outlet valve connected with said outlet pipes and having an ,outlet and means connecting said outlet with that outlet pipe which is subjected to greatest pressure; a filling cylinder having an outlet opening, a piston in said filling cylinder, a piston rod connected with the last-mentioned piston, another piston connected with the last-mentioned piston rod, another cylinder enclosing the last-mentioned piston rod, a valve connected with said outlet opening and said outlet pipes and having means connecting said outlet opening with that outlet pipe which is subjected to lesser pressure; separate piston rods connected with said pistons, separate pressure-producing means connected with said piston rods, two projections carried by one of said piston rods, two other projections carried by the other one of said piston rods, a separate contact-carrying device adapted to be engaged and actuated by each of said projections, means connecting said contact-carrying devices with said pressure-producing means for moving a piston located in its rear end position toward its front end position when the other piston is adjacent its front end position and thereupon relieving pressure from the first-mentioned piston, and a valve connected with the last-mentioned cylinder and said two pressure-producing means and having means connecting the last-mentioned cylinder with those of the two pressure-producing means which have the greatest pressure.

References Cited by the Examiner UNITED STATES PATENTS 2,660,955 12/53 Kent et al. 103-49 2,876,704 3/59 Collion et al. 103-49 LAURENCE V. EFNER, Primary Examiner.

ROBERT M. WALKER, Examiner. 

1. APPARATUS FOR THE CONTINUOUS EJECTION OF PRESSED METERIAL COMPRISING, IN COMBINATION, TWO ALTERNATELY OPERATING PRESSES, EACH OF SAID PRESSES COMPRISING A CYLINDER, A PISTON MOVABLE IN SAID CYLINDER, AND PISTON-ACTUATING MEANS CONNECTED WITH SAID PISTON, THE TWO PISTONS BEING MOVABLE IN OPPOSITE DIRECTIONS FROM FRONT END POSITIONS TO REAR END POSITIONS AND VICE VERSA; MEANS FORMING A SINGLE OUTLET FOR THE EJECTED MATERIAL , MEANS CONNECTED WITH THE LAST-MENTIONED MEANS AND SAID CYLINDERS FOR FEEDING THE MATERIAL TO BE PRESSED INTO A CYLINDER AND CAUSING THE MATERIAL TO MOVE THE PISTON LOCATED IN THAT CYLINDER INTO ITS REAR END POSITION BEFORE THE PISTON IN THE OTHER CYLINDER HAS REACHED ITS FRONT END POSITION, AND A SEPARATE HYDRAULIC DEVICE FOR MOVING THE TWO PISTONS ALTERNATELY FROM THEIR REAR END POSITIONS TO THEIR FRONT END POSITIONS TO ALTERNATELY EJECT THE MATERIAL WHICH HAS BEEN FED TO SAID PISTONS WITH SUBSTANTIALLY THE SAME EJECTION SPEED THROUGH SAID OUTLET, SAID DEVICE COMPRISING MEANS ACTUATED BY THE PISTON-ACTUATING MEANS OF ONE PISTON WHILE SAID ONE PISTON IS BEING MOVED BY THE MATERIAL TOWARD ITS REAR END POSITION FOR MOVING THE OTHER PISTON FROM ITS REAR END POSITION TO ITS FRONT END POSITION, AND SEPARATE MEANS ACTUATED BY THE PISTON-ACTUATING MEANS OF SAID OTHER PISTON WHILE SAID OTHER PISTON IS BEING MOVED BY THE MATERIAL TOWARD ITS REAR END POSITION FOR MOVING SAID ONE PISTON FROM ITS REAR END POSITION TO ITS FRONT END POSITION, THE TWO LAST-MENTIONED MEANS MOVING A PISTON FROM ITS REAR END POSITION TOWARD ITS FRONT END POSITION BEFORE THE OTHER PISTON HAS REACHED ITS FRONT END POSITION. 